net: igmp: Use ingress interface rather than vrf device

Anuradha reported that statically added groups for interfaces enslaved
to a VRF device were not persisting. The problem is that igmp queries
and reports need to use the data in the in_dev for the real ingress
device rather than the VRF device. Update igmp_rcv accordingly.

Fixes: e58e41596811 ("net: Enable support for VRF with ipv4 multicast")
Reported-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 498706b072fb70e1ffe6b5dba817816db5a4cfa7..caf2f1101d027b7b6e8d9683887e16c7bd4a8438 100644 (file)
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1007,10 +1007,18 @@ int igmp_rcv(struct sk_buff *skb)
 {
        /* This basically follows the spec line by line -- see RFC1112 */
        struct igmphdr *ih;
-       struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
+       struct net_device *dev = skb->dev;
+       struct in_device *in_dev;
        int len = skb->len;
        bool dropped = true;
 
+       if (netif_is_l3_master(dev)) {
+               dev = dev_get_by_index_rcu(dev_net(dev), IPCB(skb)->iif);
+               if (!dev)
+                       goto drop;
+       }
+
+       in_dev = __in_dev_get_rcu(dev);
        if (!in_dev)
                goto drop;